A method for connecting a film-coated electric wire to a subject member is disclosed in JP-A-5-38583. A terminal is provided by shaping a conductive plate made of copper or copper alloy into a U-shape. A film-coated electric wire is inserted in a curved portion of the U-shaped conductive member without removing the film. The curved portion is held between upper and lower electrodes. A force is applied and a current is passed between the electrodes. Heat is produced by a resistance between the electrodes and it removes the film on the wire. As a result, a core wire of the wire is exposed. The core wire is connected to the curved portion of the terminal by resistance welding.
Since the terminal is formed into the U-shape in this method, the size of the terminal cannot be reduced in size and weight. To reduce the size of the terminal, another method is disclosed in JP-A-2001-275224. In this method, a terminal is not formed into a U-shape. A film-coated wire is placed on the terminal. The terminal and the wire are held between electrodes. The electrodes produce heat that melts and removes the film on the wire. A current is passed through the core wire and the terminal to connect the core wire and the terminal together by resistance welding. With this method, the terminal and the wire are connected together without shaping the terminal into a U-shape. Therefore, the terminal can be reduced in size.
To heat and apply a force to the film-coated wire via the electrodes, the film-coated wire should be accurately arranged at a predetermined position on the terminal. If not, a contacting area between the electrodes and the wire may vary each time they are brought into contact. As a result, reliability of the connection between the terminal and the wire is reduced.